a = int(input())
b = int(input())
c = int(input())
print(7 * min(a, b // 2, c // 4))
#include <bits/stdc++.h>
using namespace std;
int main()
{
int a,b,c;
cin>>a>>b>>c;
for (size_t i = 0; c<a*4 || b<a*2; i++)
{
a--;
}
cout<<a+(a*2)+(a*4)<<endl;
}
867A - Between the Offices | 1569A - Balanced Substring |
260A - Adding Digits | 1698C - 3SUM Closure |
1029B - Creating the Contest | 1421A - XORwice |
1029A - Many Equal Substrings | 1675D - Vertical Paths |
1271C - Shawarma Tent | 805A - Fake NP |
1163A - Eating Soup | 787A - The Monster |
807A - Is it rated | 1096A - Find Divisible |
1430C - Numbers on Whiteboard | 1697B - Promo |
208D - Prizes Prizes more Prizes | 659A - Round House |
1492C - Maximum width | 171B - Star |
1512B - Almost Rectangle | 831B - Keyboard Layouts |
814A - An abandoned sentiment from past | 268C - Beautiful Sets of Points |
1391C - Cyclic Permutations | 11A - Increasing Sequence |
1406A - Subset Mex | 1365F - Swaps Again |
50B - Choosing Symbol Pairs | 1719A - Chip Game |